In recent years a wide variety of parental and urological solutions have become available pre-packaged in sterile non-pyrogenic single-dose liquid containers for intravenous and urological administration. Typically, such single-dose containers, of which the 50 milliliter to 1 liter "Viaflex" and 1 liter to 3 liter "Uromatic" containers marketed by Baxter Travenol Laboratories, Inc. are examples, have been in the form of flexible bags formed from two sheets of polyvinylchloride or similar biologically compatible material heat-sealed along the margins of a central body section thereof to form a liquid chamber of the desired volume. A port section, consisting of one or more ports, is typically provided at one end of the central portion for connection with a separately packaged administration set or irrigation means, and a tab-like hang flap section having an aperture for hanging the container in an elevated position with respect to a patient is typically provided at the other end. One or more depressed rib portions, formed by heat seals between the flap sections of the two sheets, were typically included in the container construction.
To maintain single-dose liquid containers sterile, the containers are typically packaged in an overpouch, which, like the containers, may be formed from two sheets of flexible non-pyrogenic material heat sealed along their margins. The overpouch and container combination are subjected to autoclaving wherein they are heated to a temperature sufficient to insure complete sterilization.
To minimize the volume required for storage, it is desirable that the container and overpouch combination be as compact as possible for a given volume of solution. To this end, it has become conventional to fold the port and end flap sections over the central body section of the container, thereby reducing the overall length of the container and the required length of the overpouch. While this arrangement has proven generally satisfactory, it has been found that on occasions the surface of the folded flap section tended to adhere to the underlying exterior surface of the body section during the autoclaving process, with the result that upon subsequent opening of the overpouch and peeling back of the hang flap section the container was unsuitable for use. The depressed rib portions provided on the hanger flap section were only slightly effective in reducing this tendency for adhesion.
One solution to the adhesion problem was the provision of a polyethylene separator sheet between the adjacent surfaces of the hang flap and body sections of the container. Unfortunately, placement of this sheet during packaging of the container within the overpouch complicated the manufacturing process, thereby increasing the cost of manufacture as well as the material cost of the container. The present invention is directed to an improved construction for the liquid container which minimizes the tendency for such adhesion with minimal increase in the manufacturing cost of the container.
Accordingly, it is a general object of the present invention to provide a new and improved container for parental and urological solutions.
It is a more specific object of the present invention to provide a new and improved container for parental and urological solutions which can be compactly packaged in an overpouch and autoclaved without adhesion of the hang flap section to the body section thereof.